Robert Swann and Ezra Black worked together for two weeks at Flushing Meadows Park. They were seasonal employees for the city's Parks Department. They worked as custodians. Over those two weeks, Swann later claimed, Black bullied him. On September 4, 2012, Swann fatally stabbed Black, who was 31.

Earlier this month a Queens jury convicted Swann, who is now 53, of first-degree manslaughter. And on Monday Queens Supreme Court judge Ira Margulis sentenced Swann to 25 years in prison, the maximum sentence for the charge.

Swan had worked at the park for five months. The troubles began, however, when he began working side-by-side with Black in August 2012. In his statement to police, Swann said that Black called him names and threatened him, and that he complained to his supervisors about this. Two of those supervisors, however, testified that they never knew about the conflict.

According to prosecutors, Swann pulled out the knife after Black ordered him to pick up a garbage bag in a lot behind Al Oerter Recreation Center.

When Swann confronted Black, Black took a swing at him, Swann claimed in his statement. So he stabbed him in the stomach. He then fled the scene, tossing away the knife and clothes he was wearing in a grassy field at the park.

Police found him that day. Upon arrest, Swann admitted to the crime, prosecutors said.

"I was scared and mad, he threatened me one too many times. I should have just smacked him in the face, but I didn't," Swann told the police, the New York Post reported. "He was so, so disrespectful to everyone, the supervisors, the other workers, everyone! All these nice people it's not right."

The jury acquitted him on charges of criminal possession of a weapon and tampering with physical evidence. The manslaughter conviction carried a sentencing range of five to 25 years.

"The defendant has now been held accountable for his senseless actions and will spend considerable time behind bars for resorting to violence and taking an innocent life," Queens District Attorney Richard Brown said in a statement.